Device for excluding slag and other floating impurities from molten metal as the metal is poured into a mold

ABSTRACT

A device for excluding slag and other floating impurities from molten metal as the metal is poured into a mold. The device is positioned in the pouring basin of the mold and is constructed to float as the metal is poured into the pouring basin so as to permit only the lower substantially impurity-free stratum of the molten metal to enter the mold cavity.

United States Patent McLean.

[54] DEVICE FOR EXCLUDING SLAG AND OTHER FLOATING IMPURITIES FROM MOLTEN METAL AS THE METAL IS POURED INTO A MOLD [72] Inventor: Neil J. McLean, Route 3, Box 4678,

Plymouth, Ind. 46563 [22] Filed: June 10, 1970 [21] App]. No.: 45,025

521 US. Cl ..l64/362, 164/134 51 1111.01 ..B22d 37/00, B22d 43/00 58 Field of Search ..164/362, 364, 358,412, 134; 249/204, 205; 141/46, 301, 115; 222/477,

1451 Aug. 1, 1972 Primary Examiner-Robert D. Baldwin Attorney-O1tsch & Knoblock [57] ABSTRACT A device for excluding slag and other floating impurities from molten metal as the metal is poured into a mold. The device is positioned in the pouring basin of the mold and is constructed to float as the metal is poured into the pouring basin so as to permit only the [5 6) Rekrenm Cited lower substantially impurity-free stratum of the molten UNITED STATES PATENTS metal to enter the mold cavity.

1,696,506 12/1928 Smith ..222/563 X 3 Chins, 4 Drawing Figures f l 1 I f%- P'ATENTEDAUM me I 3.680.628

1' NVEN TOR.

ATTORNEYS DEVICE FOR EXCLUDING SLAG AND OTHER FLOATING IMPURITIES FROM MOLTEN METAL AS THE METAL IS POURED INTO A MOLD SUMMARY OF THE INVENTION This invention relates to a means for excluding slag and other floating impurities from molten metal and has specific application to the separation of such impurities as the molten metal is poured into a mold.

This invention concerns a device having parts which rest upon the bottom of the pouring basin of a mold. The molten metal is poured into the basin and around or through the device, depending upon the construction thereof. The device is constructed of material having a specific gravity so related to the specific gravity of the molten metal that the device is caused to float as the metal is poured into the basin and permits the lower substantially impurity-free portion or layer, hereinafter referred to as stratum, of the molten metal within the basin to enter the sprue of the mold. Unlike the slag excluding device disclosed in US. Pat. No. 967,012, granted Aug. 9, 1910, no special anchoring means mounted to or designed as a part of the mold is required to position the device of this invention within the pouring basin as the mold is being filled with the molten metal.

Accordingly, it is an object of this invention to provide a device of economical construction for excluding slag and other floating impurities from poured molten metal.

Another object of this invention is to provide a device for excluding slag and other floating impurities from poured molten metal which is adaptable for use in molds constructed in accordance with ordinary molding techniques and without special adaptive features being applied to or forming a part of the mold.

. Other objects of this invention will become apparent upon a reading of the inventions description.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view of a mold showing one embodiment of the device of this invention utilized therewith.

FIG. 2 is an enlarged perspective view of the embodiment of the device shown in FIG. 1.

FIG. 3 is a fragmentary sectional view of a mold showing another embodiment of the device of this invention utilized therewith.

FIG. 4 is an enlarged perspective view of the embodiment of the device shown in FIG. 3 with portions thereof broken away for purposes of illustration.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The preferred embodiments illustrated are not intended to be exhaustive or to limit the invention to the precise forms disclosed therein. They are chosen and described in order to best explain the principles of the invention and its application and practical use so as to enable others skilled in the art to best utilize the invention.

Referring to the embodiment illustrated in FIGS. 1 and 2, the reference numeral refers to a mold having a cope or top part 12 and a nowel or bottom part 14 which are both enclosed by a two-part flask 16. Cope l2 and nowel l4 cooperate to define gates 20 which lead into a mold cavity 18 having a configuration of the part which is to be molded. Cope 12 includes a pouring basin 22 which is interconnected to gates 20 by a sprue 24. To facilitate the pouring of the molten metal, pouring basin 22 includes a pocket part 26 which is spaced from sprue 24 and into which the metal is poured from a ladle or similar container.

The impurity excluding device of this embodiment is designated by the reference numeral 28. Device 28 includes a stem 30 which is preferably of an inverted truncated cone shape, but which may be cylindrical in shape. Device 28 includes a concentric head portion 32 at the large diameter end of stem 30. Head portion .32 includes a lower annular face 34. The upper marginal part of head portion 32 terminates in an annular flange portion 36 having a lower face 38 which is upwardly spaced from and which parallels the plane of face 34 of the head portion.

Before the molten metal is poured into mold 10, the device 28 is positioned with its stem 30 inserted with clearance into sprue 24. Face 34 of head portion 32 of the device rests upon bottom wall 40 of the mold pour 1 ing basin 22. The diameter of head portion 32 exceeds the diameter of sprue 24 so that face 34 of the head portion makes circumferential engagement with the upper marginal edge of the sprue and thereby serves to seal the sprue. With the device 28 so supported in po uring basin 22 of mold l0, face 38 of flange portion 36 of the device is spaced from the bottom wall 40 of the pouring basin, as illustrated in FIG. 1. Device 28 is constructed from a material, such as bonded core sand, having a specific gravity which is less than the specific gravity of the molten metal and which is so related to the specific gravity of the molten metal that as the metal is poured into the pocket part 26 of pouring basin 22, first filling the pocket part and then flowing into the remainder of the basin, head portion 32 of device 28 is first surrounded by the metal, and as the level of the metal eventually reaches face 38 of flange portion 36 of the device, device 28 is caused to be lifted by the metal with its face 34 being separated from bottom wall 40 of the pouring basin to expose sprue 24. The length of stem 30 preferably exceeds the depth of pouring basin 22 at sprue 24 so that the stem remains at all times within sprue 24 during pouring and thereby serves to prevent a shifting of device 28 from the sprue area and to prevent a vortex from forming in the metal as it passes down the sprue 24. As device face 34 is separated from basin bottom wall 40 and the opening into sprue 24 is exposed, the lower, substantially impurity-free, stratum of the metal flows between face 34 and wall 40 into the sprue. The spacing between the plane of face 34 and the plane of face 38 of flange portion 36 is sufficient to prevent the upper stratum or portion of the molten metal which contains the floating impurities from flowing around the lower edge 33 of head portion 32 and by its face 34 into the sprue. Head portion 32 of the device 28 also prevents the floating impurities from entering the sprue once pouring ceases and as device 28 is permitted to settle within pouring basin 22 with its face 34 again making circumferential contact with wall 40 of the pouring basin at the upper margin of sprue 24 to seal the sprue.

Another embodiment of the impurity excluding device of this; invention is illustrated in FIGS. 3 and 4 andis designated by the reference numeral 42. Device 42 is of a cylindrical shape having a longitudinal bore 44' therethrough. Device 42 has a lower end face ,46 which definesthelower opening 48 of bore 44. Bore 44 includes a central. portionSQ which is of a smaller diameter than lower opening 48 of the bore. Central portion 50 of bore 44 is separated from lower bore opening 48 by an annular face part 52 which is inset or spaced inwardlyof end face '46 of device 42. Longitudinal bore 44 of device 42 includes an upper bore portion 54 having a side wall 55 which diverges upwardly from central bore portion 50 and which terminates at upper end face 56 ofdevice 42.

'Asshown'in FIG. 3, the pouring basin 22 of mold includes 'a' pocket part 26. which is laterally spaced from'sprue 24 of the mold and which includes a flat bottom wall 58. lmpurity'excluding device 42 is seated within pocket part 26' of mold 10 with its lower end face 46 abutting and making circumferential contact with bottom wall 58 of thepocket part. Device 42 is constructed from material, such as bonded core sand, having a specific gravity which is less than and so related to the specific gravity of the molten metal" being poured into mold 10 that as the metal is'poured into upper boreportion 54 of the device from a ladle or similar container, themetal will first collect and pool within the area 60 of device 42 between face part 52 thereof and wall 58 of the basin 22 and then as the level of the metal within area 60 reaches face part 52 the device will be lifted by the metal. As the device 42 is lifted or floated by the metal pooling within area 60 therein, lower end face 46 of the device is separated from wall 58 of the basin to permit the lower, substantially impurity-free stratum of pooled metal within area 60 'to flow around end face 46 into the remainder of pouring basin 22 and down sprue 24.

The spacing between the plane of lower end face 46 and face part 52 of device 42 and the surface area of face part 52 are of importance so as to allow the device to rise from wall 58 of the basin 22 and yet retain the upper impurity-containing stratum or portion of pooled metal in area 60 within the device as the lower stratum mold with lower end face 46 thereof again contacting the bottom wall 58 of the basin, thus preventing the impurities collected within the device from flowing into a the remainder of the basin.

It is to be understood that the invention herein described is not to be limited to the details given but that it may be modified within the scope of the appended claims. r

What I claim is:

1. In combination with a mold having a pouring basin which includes a bottom wall and a sprue in said bot-' tom wall, a device formed of bonded c'or'e sand or similar heat resisting material for excluding floating impurities from molten metal when poured into said mold comprising a vertical stem extending with clearance into said-sprue, a head portion formed at the upper end of said stem, said head portion including acontinuous ilfaiifniifil 'fl lfiifi'iliifgi'u u f'fi' $5 making contact with said bottom wall circumferentially about the upper margin of said sprue to thereby seal the sprue, said flange being spaced from said lower face and from said bottom wall, said device having a specific gravity so related to the specific gravity of said molten metal that as said molten metal fills said pouring basin and contacts said flange the head will be lifted from contact with said bottom wall to expose said sprue and thereby permit the lower substantially impurity-free stratum of said molten metal within said basin to enter said sprue.

2. The combination of claim 1' wherein the length of said stem exceeds the depth of said pouring basin over the sprue to enable said stem to remain within said sprue as said head portion is lifted from the bottom wall of said pouring basin.

3. The combination of claim I wherein said flange includes a lower face portion having a surface area so related to the weight of said device that said head portion is lifted from the bottom wall of said pouring basin as the level of said molten metal in said pouring basin contacts said lower face portion. 

1. In combination with a mold having a pouring basin which includes a bottom wall and a sprue in said bottom wall, a device formed of bonded core sand or similar heat resisting material for excluding floating impurities from molten metal when poured into said mold comprising a vertical stem extending with clearance into said sprue, a head portion formed at the upper end of said stem, said head portion including a continuous flange extending laterally outwardly from the upper marginal part of said head portion and a lower face making contact with said bottom wall circumferentially about the upper margin of said sprue to thereby seal the sprue, said flange being spaced from said lower face and from said bottom wall, said device having a specific gravity so related to the specific gravity of said molten metal that as said molten metal fills said pouring basin and contacts said flange the head will be lifted from contact with said bottom wall to expose said sprue and thereby permit the lower substantially impurity-free stratum of said molten metal within said basin to enter said sprue.
 2. The combination of claim 1 wherein the length of said stem exceeds the depth of said pouring basin over the sprue to enable said stem to remain within said sprue as said head portion is lifted from the bottom wall of said pouring basin.
 3. The combination of claim 1 wherein said flange includes a lower face portion having a surface area so related to the weight of said device that said head portion is lifted from the bottom wall of said pouring basin as the level of said molten metal in said pouring basin contacts said lower face portion. 